A conclusion is the final idea left with the reader at the end of an essay. Without it, an essay would be unfinished and unfocused. A conclusion should link back to the essay question and briefly ...

Before writing a paper, authors are advised ... emphasizing the key conclusions of the research and yet providing the full supporting details required by others in the field in online-only form.

Without a conclusion, your writing may seem unfinished or your overall aim may not be clear. The conclusion is your final chance to leave an impression on the reader.